Nucleophilic and electrophilic cyclization of N-alkyne-substituted pyrrole derivatives: Synthesis of pyrrolopyrazinone, pyrrolotriazinone, and pyrrolooxazinone moieties

• Işıl Yenice,
• Sinan Basceken and
• Metin Balci

Beilstein J. Org. Chem. 2017, 13, 825–834, doi:10.3762/bjoc.13.83

• pyrrole esters is described. Efficient routes towards the synthesis of pyrrolopyrazinone, pyrrolotriazinone and pyrrolooxazinone have been developed. First, N-alkyne-substituted pyrrole ester derivatives were synthesized. Introduction of various substituents into the alkyne functionality was accomplished

• , cyclization of N-alkyne-substituted methyl 1H-pyrrole-2-carboxylates with iodine only resulted in the formation of the 6-endo-dig cyclization product regardless of the substitution of the alkyne functionality. Keywords: alkyne cyclization; pyrrole; pyrrolooxazinone; pyrrolopyrazinone; pyrrolotriazinone

• , nannozinone B (5, Figure 2), containing a pyrrolopyrazinone moiety was isolated from a myxobacterium, Nannocystis pusilla [11]. The alkaloid peramine (6, Figure 2), isolated from endophyte-infected perennial ryegrass, has feeding deterrent activity against insects [12][13]. An efficient and straightforward